JP2010244645A - Method for manufacturing resin stamper, and method for manufacturing magnetic recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily obtain a discrete type magnetic recording medium compatible with high density recording and a stamper applicable to a manufacturing process of the medium. <P>SOLUTION: An injection-molded recess and protrusion pattern surface of a resin stamper is subjected to a dry etching process for surface treatment. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a stamper used for manufacturing a magnetic recording medium having a discrete track on the surface of a magnetic recording layer.

  Currently, a discrete track (DTR) medium is being studied as one of means for increasing the density of magnetic disks. This is to increase the recording density in the track direction by providing grooves on the medium surface to divide the track. Also, since the servo pattern can be engraved with unevenness at the same time as providing grooves between tracks, if the device is devised for patterning, it is not necessary to record servo signals one by one as before, improving productivity. it can.

  In the process of manufacturing the DTR medium, an imprint stamper is pressed against the resist applied on the surface of the magnetic recording layer, the uneven pattern is transferred to the resist, and the magnetic recording layer is processed using the resist as a mask (for example, Patent Document 1).

  As such an imprint stamper, a Ni stamper produced and duplicated by an electroforming process has been used as a father stamper, a mother stamper, or a sun stamper. However, when the electroforming process is used, there is a problem that it takes a long manufacturing time of about 1 hour per Ni stamper. On the other hand, if the first Ni stamper is produced as a father stamper by an electroforming process, and the mother stamper or sun stamper produced thereafter is produced by using an injection molding process, the production is as short as several seconds per sheet. A resin imprint stamper can be obtained in time.

  This injection molding process has been used to make optical disks.

  In this discrete track type magnetic recording medium, it is important how narrow and smooth the track groove is. For example, the density currently being investigated is several tens of nanometers as the track pitch, but in order to secure the signal-to-noise ratio of the signal, it is necessary to widen the land portion where the signal is recorded, that is, the convex portion or the portion where the magnetism is active. In other words, it is desirable that the track groove, that is, the concave portion or the portion that has lost the magnetism is as narrow as possible. In the future, if the track pitch becomes narrower as the recording density increases, the track groove becomes narrower. Further, since the edge roughness of the track groove is also a noise source, it naturally affects the quality of the recording / reproducing signal.

  The necessity of narrowing the groove will be described below in comparison with an optical disc. In the case of an optical disk, there are land groove recording and groove recording. In land group recording, marks must be recorded on both the land (island) portion and the groove (groove) portion, so the ratio of land to groove is about 1: 1. Is desirable. On the other hand, in the groove recording, there is a case where recording is actually performed only on the groove portion and a case where recording is performed only on the land portion. In either case, if the recording portion (groove or land) is too narrow, the recording signal is reacted. The area (or volume) where the recording mark can be made is narrow, and the signal-to-noise ratio is deteriorated without writing a signal. Further, since the optical disc has a recording / reproducing light spot larger than the track pitch to be recorded, if the portion (land or groove) where recording is not performed is too narrow, the recording mark of the adjacent track is erroneously recognized (or erroneously recorded). Therefore, in the case of an optical disk, neither the groove nor the land can be made too narrow. On the other hand, if it is too wide, the recording density is lowered, so that an optimum value exists. For example, in an example of a Blu-ray disc, the land-and-groove pitch is about 0.32 μm, and the land-to-groove width ratio is about 1: 1, and this pitch is about five times larger than a discrete magnetic disk. On the other hand, in the case of a magnetic disk, particularly a DTR medium, recording is performed on the land portion referred to here. However, if the land is too narrow, the area where a recording mark can be formed in response to a recording signal is small as in the case of an optical disk, The recording mark is small and the SN ratio is deteriorated. However, in the case of a magnetic disk, since the effective area of the recording / reproducing head is smaller than the recording track pitch, erroneous recognition of adjacent tracks can be ignored. If the adjacent track is physically and magnetically separated by the groove, erroneous recording can be ignored. Therefore, when increasing the recording density, there is a limit to narrowing the land, but the groove (groove) is more advantageous in terms of density as long as it is divided from adjacent tracks.

  Thus, although the injection molding process that has been used for the production of optical discs is considered to be useful for the formation of stampers used to form uneven patterns on the surface of discrete media, the land width and groove width required for the uneven patterns Unlike the optical disc, since the pitch is small, a high quality stamper cannot be obtained even if the technology used in the optical disc is used as it is, and further improvement is required.

JP 2003-157520 A

  The present invention has been made in view of the above circumstances, and an object of the present invention is to easily obtain a discrete magnetic recording medium that can cope with high-density recording and a stamper applicable to the manufacturing process of the medium.

The resin stamper manufacturing method of the present invention is a resin applied when transferring the concavo-convex pattern to an ultraviolet curable resin used as a mask for forming a discrete track composed of the concavo-convex pattern on the surface of the magnetic recording layer. A stamper manufacturing method comprising:
The method includes a step of injection molding a resin stamper having a concavo-convex pattern surface for the discrete track, and a step of subjecting the concavo-convex pattern surface of the resin stamper to a dry etching process to perform a surface treatment.

The method for producing a magnetic recording medium of the present invention includes a step of injection molding a resin stamper having a concavo-convex pattern surface corresponding to a concavo-convex pattern provided as a discrete track on the surface of a magnetic recording layer,
Subjecting the concave / convex pattern surface of the resin stamper to a dry etching process to perform a surface treatment;
Bonding the surface of the magnetic recording layer of the magnetic recording medium and the surface-treated uneven pattern surface of the resin stamper through an uncured ultraviolet curable resin layer;
A step of irradiating the uncured UV-curable resin layer with UV rays to cure it,
Peeling off the resin stamper to form an ultraviolet curable resin layer having a concavo-convex pattern transferred on one surface of the magnetic recording medium; and performing dry etching using the ultraviolet curable resin layer as a mask to form a surface of the magnetic recording layer And a step of forming a concavo-convex pattern.

  According to the present invention, a discrete magnetic recording medium that can cope with high-density recording and a stamper applicable to this medium can be easily obtained.

It is the schematic showing an example of the structure of the metal mold | die for resin stamper molding concerning this invention. It is a figure showing the process of forming a discrete track type magnetic recording medium. It is a figure showing the manufacturing process of a metal stamper. It is a figure showing an example of the magnetic recording / reproducing apparatus using the discrete type magnetic recording medium of this invention. It is a figure showing an example of the mode of the concavo-convex pattern surface before and after surface treatment of the resin stamper concerning the present invention. It is a figure showing an example of the mode of the concavo-convex pattern surface before and after surface treatment of the resin stamper concerning the present invention. It is a figure showing an example of the mode of the concavo-convex pattern surface before and after surface treatment of the resin stamper concerning the present invention. It is a figure showing an example of the mode of the concavo-convex pattern surface before and after surface treatment of the resin stamper concerning the present invention.

  The method for producing a resin stamper according to the present invention includes a concavo-convex pattern applied when transferring a concavo-convex pattern to an ultraviolet curable resin used as a mask for forming a discrete track comprising a concavo-convex pattern on the surface of a magnetic recording layer. In this method, a resin stamper having a surface is manufactured by injection molding, and the uneven pattern surface of the resin stamper is subjected to a dry etching process to perform surface treatment.

  According to one aspect of the method for producing a resin stamper of the present invention, when the concave / convex pattern surface of the resin stamper is subjected to a dry etching process, the convex portion is narrowed to widen the concave portion, and the resin stamper having a wide concave portion is formed. Can be formed.

  According to another aspect of the method for producing a resin stamper of the present invention, when the concave / convex pattern surface of the resin stamper is subjected to a dry etching process, the convex portion is narrowed to widen the concave portion, and the convex portion is vertically cut. The surface can be triangular.

  According to still another aspect of the resin stamper manufacturing method of the present invention, when the uneven pattern surface of the resin stamper is subjected to a dry etching process, the uneven pattern surface of the resin stamper is maintained while maintaining the uneven pattern surface. Roughness can be reduced and smoothened.

  By reducing the roughness of the concavo-convex pattern surface of the resin stamper and making it smooth, it is possible to prevent the concavo-convex pattern surface of the discrete magnetic recording medium from being roughened, so that a magnetic recording medium with low noise can be obtained.

  Further, when the transfer of the concavo-convex pattern from the mother stamper and the father stamper is repeated, the exposure apparatus using an electron beam is cheaper if the concave portion width is largely different from the convex portion width. In order to record a thin groove, a higher acceleration voltage is required, and the apparatus becomes extremely expensive. Further, if the electron beam used for exposure becomes thinner, the amount of current decreases, and the required master recording time is not a realistic value for the mass production process. In addition, it is difficult to reduce the roughness by smoothing the track grooves.

  On the other hand, using the method of the present invention, after transferring a concavo-convex pattern having a groove width equivalent to the land width to the resin stamper, the roughness of the concavo-convex pattern surface is reduced and smoothed by a dry etching process, or If the convex portion width is processed to be smaller than the concave portion width, a resin stamper having a concave / convex pattern for forming a discrete track can be formed accurately and easily at low cost. The longitudinal section of the convex portion may be rectangular or triangular.

A method for producing a magnetic recording medium of the present invention is a method for forming a concavo-convex pattern on the surface of a magnetic recording medium using the resin stamper,
For example, under vacuum, the step of bonding the surface of the magnetic recording layer of the magnetic recording medium and the uneven surface of the resin stamper that has been surface-treated through an uncured ultraviolet curable resin layer,
A process of irradiating the uncured UV curable resin layer with UV light to cure it,
A step of peeling the resin stamper to form an ultraviolet curable resin layer having a concavo-convex pattern transferred on one side of the magnetic recording medium, and dry etching using the ultraviolet curable resin layer as a mask, thereby forming irregularities on the surface of the magnetic recording layer. Forming a pattern.

According to one aspect of the method for producing a magnetic recording medium of the present invention,
A step of injection molding a resin stamper having a concavo-convex pattern surface corresponding to the concavo-convex pattern provided as a discrete track on the surface of the magnetic recording layer;
A step of subjecting the concave / convex pattern surface of the resin stamper to a dry etching process, narrowing the convex portion to widen the concave portion, and forming a resin stamper having a wide concave portion;
For example, under vacuum, the step of bonding the magnetic recording layer surface of the magnetic recording medium and the concave / convex pattern surface of the resin stamper having the wide concave portion through an uncured ultraviolet curable resin layer,
A process of irradiating the uncured UV curable resin layer with UV light to cure it,
Peeling the resin stamper to form an ultraviolet curable resin layer having a concavo-convex pattern having a wide convex portion transferred on one side of the magnetic recording medium;
There is provided a method comprising a step of performing dry etching using an ultraviolet curable resin layer as a mask to form a concavo-convex pattern having wide convex portions on the surface of a magnetic recording layer.

  According to another aspect of the method for manufacturing a magnetic recording medium of the present invention, the concave / convex pattern surface of the resin stamper is subjected to a dry etching process, the convex portion is thinned to widen the concave portion, and the wide concave portion is provided. In the above step of forming the resin stamper, the concave portion can be widened by narrowing the convex portion until the longitudinal section thereof has a triangular shape. By using the resin stamper having the wide concave portion, the concave / convex pattern having the wide convex portion similar to the one aspect of the method of manufacturing the magnetic recording medium of the present invention can be formed on the surface of the magnetic recording layer.

  Using the method of the present invention, after transferring a concavo-convex pattern having the same groove width to the land width to the resin stamper, if the convex width is processed smaller than the concave width by a dry etching process, the concave width can be easily and accurately obtained. A magnetic recording medium having a discrete track smaller than the convex width can be formed.

  According to still another aspect of the method for manufacturing a magnetic recording medium of the present invention, the uneven pattern surface of the resin stamper is subjected to a dry etching process, and the uneven surface of the uneven pattern surface of the resin stamper is maintained while maintaining the unevenness of the uneven pattern surface. A reduced and smooth resin stamper can be prepared and used to form an uneven pattern on the surface of the magnetic recording layer.

  By reducing the roughness of the concavo-convex pattern surface of the resin stamper and making it smooth, it is possible to prevent the concavo-convex pattern surface of the discrete magnetic recording medium from being roughened, so that a magnetic recording medium with low noise can be obtained.

In the method for manufacturing a resin stamper and the method for manufacturing a magnetic recording medium according to the present invention, Ar gas or a mixed gas of CF ₄ and O ₂ is used when the uneven pattern surface of the resin stamper is subjected to a dry etching process. be able to.

  When Ar gas is used when the concave / convex pattern surface of the resin stamper is subjected to a dry etching process, the roughness of the concave / convex pattern surface of the resin stamper is maintained and the roughness of the concave / convex pattern surface is reduced, or Furthermore, the convex portion can be narrowed to widen the concave portion, and a resin stamper having a convex portion having a rectangular longitudinal section and a wide concave portion can be formed.

Also, if a mixed gas of CF ₄ and O ₂ is used when the concave / convex pattern surface of the resin stamper is subjected to a dry etching process, the convex portion is narrowed to widen the concave portion, and the vertical section of the convex portion is triangular. can do.

  Hereinafter, the present invention will be described in more detail with reference to the drawings.

  FIG. 1 is a schematic view showing an example of the configuration of a resin stamper molding die according to the present invention.

  As shown in the figure, the resin stamper molding die 30 has a fixed side mold plate 1 having a metal stamper mounting surface 12 mirror-polished in a random direction, a metal stamper 3, and a fixed side mold plate 1. , And a moving side mold plate 2 arranged opposite to each other with a metal stamper 3 interposed therebetween. The metal stamper 3 has, for example, a spiral or concentric circular screet track, and a concave / convex pattern surface 3a having a concave / convex pattern having the same width of the concave and convex portions according to the servo shape. Reference numeral 40 schematically represents a disk-shaped resin stamper that can be injection-molded using the mold 30.

  FIG. 2 is a sectional view showing a process of forming a magnetic recording medium having a discrete track using a resin stamper obtained from the mold shown in FIG.

  In order to form a magnetic recording medium using a resin stamper, a surface-treated resin stamper 40 is obtained by injection molding using the mold shown in FIG. A metal having a concavo-convex pattern 3a corresponding to a discrete track and a servo pattern, for example, a Ni stamper 3 is placed on the fixed-side mold plate 1 so that the concavo-convex pattern 3a faces the moving-side mold plate 2. 1 and the movable side mold plate 2 are combined, and the molten injection molding resin is injected into the cavity from the injection hole 6 leading to the central part of the fixed side mold plate 1. Subsequently, after pressurizing by mold clamping, cooling is performed to perform injection molding. The center portion of the molded body is punched out with a cut punch (not shown), and a disk-shaped resin stamper 40 having a center hole is obtained. Unevenness is carved into the surface 3a of the metal stamper 3. For this reason, the concave / convex pattern 4a is transferred to the resin stamper 40 formed using this as a mold. As the injection molding resin material, for example, cycloolefin polymer, polycarbonate, acrylic, or the like can be used.

  Next, the obtained resin stamper 40 is subjected to a dry etching process to form a surface-treated uneven pattern 4a '. Thereby, the roughness of the concavo-convex pattern surface can be reduced and smoothened while the concavo-convex pattern surface is maintained. Alternatively, the convex portion can be further narrowed to widen the concave portion, and a resin stamper having a wide concave portion can be formed.

  Next, as shown in FIG. 2A, an ultraviolet curable resin 43 is applied to the surface of the magnetic recording medium 44 having the substrate 42 and the magnetic recording layer 41 formed thereon, and this surface treatment is performed thereon. The resin stamper 40 is pressed and cured by irradiating with ultraviolet rays (UV imprint).

Subsequently, as shown in FIG. 2B, the resin stamper 40 is peeled off from the ultraviolet curable resin. The resin stamper is peeled off to expose the ultraviolet curable resin layer having the concavo-convex pattern transferred thereto. Thereafter, as shown in FIG. 2C, the ultraviolet curable resin in the pattern recesses is formed by, for example, CF ₄ gas or O ₂ gas dry etching. The residue of 43 is removed, and bottoming is performed until the surface of the magnetic recording layer 41 is exposed in the concave portion of the concave-convex pattern.

  Further, as shown in FIG. 2D, the surface of the magnetic recording layer 41 is processed by ion milling such as Ar, using the ultraviolet curable resin 43 as a mask. Thereby, unevenness of tracks and servo patterns is formed on the surface of the magnetic recording layer 41. The surface of the magnetic recording layer 41 is processed by ion milling.

  Thereafter, as shown in FIG. 2E, the ultraviolet curable resin 43 is removed by dry etching to obtain a discrete track magnetic recording medium 44 '.

  If necessary, the obtained magnetic recording medium can be subjected to post-processes such as embedding a non-magnetic material in a pattern recess, applying a lubricant, and polishing a tape.

  The magnetic recording medium handled here is 1.8 inches, for example, a diameter of 48 mm ± 0.2 mm, a center hole diameter of 12.01 mm ± 0.01 mm, and a thickness of 0.508 mm ± 0.05 mm. A 5-inch medium (diameter 65 mm ± 0.2 mm, center hole diameter 20.01 mm ± 0.01 mm, thickness 0.635 mm ± 0.05 mm) can also be used.

  FIG. 3 is a diagram showing a manufacturing process of the metal stamper.

  As shown in FIG. 3A, an electron beam resist is first applied on a Si wafer.

  Next, as shown in FIG. 3B, the track and servo pattern are exposed to the electron beam resist with an electron beam.

  Subsequently, as shown in FIG. 3C, the exposed portion or the unexposed portion is dissolved by developing the electron beam resist to form the unevenness 22 'of the track and the servo pattern.

  Further, as shown in FIG. 3D, after conducting the conductive treatment on the unevenness 22 'of the electron beam resist, Ni plating is performed, and the pattern is duplicated with Ni to produce the Ni father stamper 23. .

  Thereafter, the Ni mother stamper 24 is produced from the Ni father stamper 23 by Ni plating.

  If necessary, sun stampers and daughter stampers can be created.

  Further, as shown in FIG. 3 (f), the back surface of the Ni mother stamper 24 is polished, the center hole and the outer periphery are machined to form a donut shape, and attached to the injection mold.

  In the present invention, by performing a dry etching process on a resin stamper used in a discrete track type magnetic recording medium, the track groove (corresponding to a convex portion on the resin stamper) is processed to be thin and smooth, or the track groove is formed. Make it thinner.

  FIG. 4 shows a configuration diagram of an example of a magnetic recording / reproducing apparatus using the discrete magnetic recording medium of the present invention.

  A rigid magnetic disk 121 for recording information according to the present invention is mounted on a spindle 122 and is driven to rotate at a constant rotational speed by a spindle motor (not shown). A slider 123 mounted with, for example, a single pole type recording head for recording information by accessing the magnetic disk 121 and an MR head for reproducing information is attached to the tip of a suspension 124 made of a thin plate spring. Yes. The suspension 124 is connected to one end side of an arm 125 having a bobbin portion for holding a drive coil (not shown).

  On the other end side of the arm 125, a voice coil motor 126, which is a kind of linear motor, is provided. The voice coil motor 126 is composed of a drive coil (not shown) wound around the bobbin portion of the arm 125, and a magnetic circuit composed of a permanent magnet and a counter yoke arranged so as to sandwich the coil.

  The arm 125 is held by ball bearings (not shown) provided at two positions above and below the fixed shaft 127, and is driven to rotate and swing by a voice coil motor 126. That is, the position of the slider 123 on the magnetic disk 121 is controlled by the voice coil motor 126. In FIG. 12, reference numeral 128 denotes a lid.

  FIGS. 5 to 8 are views showing the state of the concavo-convex pattern surface before and after the surface treatment of the resin stamper according to the present invention.

  Both are images measured with an AFM (Atomic Force Microscope). In this example, polycarbonate is used as the resin stamper material, the track pitch is 770 nm, and the ratio of the land to groove width is about 1: 1. The material may be cycloolefin polymer or acrylic, and the track pitch may be further packed. The surface treatment was performed with a RIE (Reactive Ion Etching) apparatus.

  Fig. 5 shows the initial shape before dry etching, Fig. 6 shows the shape after processing with Ar gas at a flow rate of 50 sccm, pressure of 1.0 Pa, power of 140 W, bias of 0 kV, and time of 5 minutes, and Fig. 7 shows the Ar gas. Using a flow rate of 50 sccm, a pressure of 1.0 Pa, a power of 200 W, a bias of 0 kV, a shape after processing for 30 seconds, FIG. 8 shows a flow rate of 10/500 sccm, a pressure of 28 Pa, a power of 700 W, and a time using a mixed gas of CF4 / O2. The shape after 30 seconds at a temperature of 35 ° C.

FIG. 6 shows that the convex portions of the pattern are narrowed by dry etching. FIG. 7 shows that the surface of the pattern becomes smooth if the processing time is short. Incidentally, the surface roughness of the initial shape in FIG. 5 is Rms = 1.00 nm, Ra = 0.716 nm, and the surface roughness of the processed shape in FIG. 7 is Rms = 0.794 nm, Ra = 0.62 nm. Furthermore, in FIG. 8, it can be seen that the convex pattern, which has a rectangular cross section, has a triangular cross section by dry etching the portion that contacts the shoulder. By using the resin stamper having a triangular cross section for mask transfer for patterning a discrete magnetic recording medium, it can be expected that a narrower track groove can be formed.

  By performing the dry etching (RIE) process on the resin stamper in this way, the track groove of the discrete magnetic recording medium can be made smooth (low roughness) and thinned.

  Next, a recording / reproducing experiment of the DTR magnetic recording medium manufactured according to the present invention was performed.

  First, the width of the groove provided on the DTR medium was set to about 25 nm. Here, the track pitch was 83 nm. At this time, a land width sufficient to make a magnetic recording mark could not be secured, and evaluation by a drive could not be performed.

  When the groove was smoothed by the method according to the present invention (short-time treatment with Ar), the LER (line edge roughness) could be reduced from 7 nm to 5 nm at 3σ. Since the groove itself is thick, the land width could not be secured and recording / reproduction could not be achieved. However, if a narrow groove is realized by the advancement of the original recording device (improvement of S), noise is reduced by lowering the LER. (N reduction), it was found that a good S / N ratio could be achieved in the future.

Further, when the groove width is reduced to 15 nm by the method according to the present invention, a land width sufficient to record a signal having a sufficient S / N ratio can be secured (the pitch itself is also 83 nm). _In both cases, the error rate was 1 × 10 ^−4.5 and reached the practical level.

  By making the track groove of the discrete track type magnetic recording medium thinner and smoother, better recording / reproducing characteristics can be obtained. This is because in order to ensure the signal-to-noise ratio of the signal, it is desirable to widen the land portion where the signal is recorded, and conversely, it is desirable to make the track groove as thin as possible. Since the edge roughness of the track groove is also a noise source, it is desirable to make it smoother in view of signal quality.

By using the present invention, a dry etching (RIE) process is performed on a resin stamper used for mask transfer to a magnetic recording medium, so that a track groove (corresponding to a convex portion on the resin stamper) is thinly and smoothly processed. Is possible. Specifically, by using Ar gas alone or a mixed gas of CF ₄ / O ₂ , the processing time can be shortened to improve the surface roughness, or the processing can be performed in a longer time to make the track thinner. .

  Also, by using a thin and smoothly processed resin stamper in this way, a discrete track magnetic recording medium having a narrower track groove, excellent signal quality, and capable of increasing the density by narrowing the track pitch is obtained. I can do it.

  The method according to the present invention can be realized by a relatively inexpensive method such as dry etching on a resin stamper, and introduces an expensive master recording apparatus such as an electron beam gun having a high acceleration voltage, which is normally performed in thinning a track. Is not necessary. Further, since it is not necessary to extremely narrow the electron beam at the time of recording the master, a sufficient beam current can be secured, and the recording of the master does not take a long time due to the insufficient dose, and the productivity is excellent.

  4a ... Uneven pattern surface, 40 ... Resin stamper, 41 ... Magnetic recording layer, 43 ... Ultraviolet curable resin layer, 44 ... Magnetic recording medium, 44 '... Discrete track type magnetic recording medium

Claims (10)

A method for producing a resin stamper applied when transferring the concavo-convex pattern to an ultraviolet curable resin used as a mask for forming a discrete track composed of the concavo-convex pattern on the surface of the magnetic recording layer,
A resin stamper comprising: a step of injection molding a resin stamper having a concavo-convex pattern surface for the discrete track; and a step of subjecting the concavo-convex pattern surface of the resin stamper to a dry etching process to perform a surface treatment. Production method.   2. The method for producing a resin stamper according to claim 1, wherein, in the surface treatment step, the convex pattern on the concave / convex pattern surface of the resin stamper is narrowed to widen the width of the concave pattern.   The method for manufacturing a resin stamper according to claim 2, wherein the convex pattern has a triangular cross section.   2. The method for producing a resin stamper according to claim 1, wherein the unevenness of the uneven pattern surface of the resin stamper is maintained and the roughness of the uneven pattern surface is reduced and smoothed by the surface treatment step. The method for manufacturing a resin stamper according to claim 1, wherein the dry etching process uses Ar gas or a mixed gas of CF ₄ and O ₂ . A step of injection molding a resin stamper having a concavo-convex pattern surface corresponding to the concavo-convex pattern provided as a discrete track on the surface of the magnetic recording layer;
Subjecting the concave / convex pattern surface of the resin stamper to a dry etching process to perform a surface treatment;
Bonding the surface of the magnetic recording layer of the magnetic recording medium and the surface-treated uneven pattern surface of the resin stamper through an uncured ultraviolet curable resin layer;
A step of irradiating the uncured UV-curable resin layer with UV rays to cure it,
Peeling off the resin stamper to form an ultraviolet curable resin layer having a concavo-convex pattern transferred on one surface of the magnetic recording medium; and performing dry etching using the ultraviolet curable resin layer as a mask to form a surface of the magnetic recording layer A method for producing a magnetic recording medium, comprising the step of forming a concavo-convex pattern on the magnetic recording medium.   By the surface treatment step, the convex pattern of the concave / convex pattern surface of the resin stamper is narrowed to widen the width of the concave pattern, and the resin stamper having a wide concave portion is used to widen the convex pattern on one side of the magnetic recording medium. 6. The method of manufacturing a magnetic recording medium according to claim 5, wherein a concavo-convex pattern having a convex portion is transferred, and a concavo-convex pattern having a wide convex portion is formed on the surface of the magnetic recording layer.   The method of manufacturing a magnetic recording medium according to claim 7, wherein the convex pattern has a triangular cross section.   7. The method of manufacturing a magnetic recording medium according to claim 6, wherein the surface treatment step reduces and smoothes the roughness of the uneven pattern surface while maintaining the unevenness of the uneven pattern surface of the resin stamper. . The method of manufacturing a magnetic recording medium according to claim 6, wherein the dry etching process uses Ar gas or a mixed gas of CF ₄ and O ₂ .

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